Trunk-selecting device



Jan. 13, 1925. 1,523,381

.4 F. A. LUNDQUIST ET AL TRUNK SELECTING DEVICE Filed NOV. 22, 1920 Dave/afar? Patented Jan. 13, 1925.

FRANK A. LUNDQUIST AND JOHN A. KROPP, OF CHICAGO,

MESNE ASSIGNMENTS, TO HENRY S.

ILLINOIS, ASSIGNORS, BY CONRAD, TRUSTEE.

TRUNK-SELECTING DEVICE.

Application filed November 22, 1920. Serial No. 425,650.

To all whom it may concern.

Be it known that we. FRANK A. LUND- outer and JoHN A. Knorr, citizens of the United States of America. residing at 4005 Irving Park Boulevard and 3889 Gladys Avenue, respectively, in the city of Chicago, county of (look, and State of Illinois, have invented certain new and useful Improvements in Trunk-Selecting Devices, of which the following is a specification.

Our invention relates in general to a trunk selecting switch for use in an automatic telephone system, and more specifically to an interrupting device for causing the automatic operation of a movable element over a series of contacts, the interrupter device being of the pneumatic type which interrupts its own source of air supply rather than a source of current as in the usual electric interrupter. This interrupter may have many uses although it is illustrated in connection with the operation of an automatic switch.

The accompanying drawing is a diagram of so much of the apparatus as is necessary to an understanding of the present invention.

In said drawing 1 is a ratchet wheel i'nounted upon and secured to a shaft 2. Pivoted at 3 is a lever 4 having a pawl 5 on its end. which pawl is arranged to engage and turn the wheel 1 when the lever is vibrated on its pivot. Connected to the lever at is a motor 6 which is in the form of a compound diaphragm and is commercially known as a sylphon. hen compressed air is admitted to the sylphon 6, the lever 4cis moved so as to cause the pawl 5 to advance the wheel 1. lVhen air is exhausted from the sylphon, the lever returns to normal position, which is that shown in the drawing.

A magnet 7 is provided with wires 8 and 5) over which it is energized from some other part of the exchange. The circuit for the magnet 7 may be closed either manually or mechanically. Adjacent to the magnet 7 is a valve 10 which is connected to compressed air supply pipe 11. The valve 10 is in the nature of a check valve which is normally closed by the pressure of the air in the pipe 11. But there is a projecting pin 12 adjacent to the armature 13 of magnet 7. lVhen the armature 13 is attracted, it engages the pin 12 to open valve 10 and permit compressed air to flow thru pipe 14- to another check valve 15 which is like valve 10 and is closed by the pressure ot the air in pipe 14.

Pivoted at 16 is a lever on an arm 17 of which is a spring 18 which is arranged to engage a pin 19 to open valve 15 when the parts are in the position shown. Supported at 20 is a spring 21, and between this spring and the arm 22 of the lever pivoted at 16, is a link or bar 23 under compression between the spring 21 and the arm 22. Another {1TH} projects between arms 25 and 26 on lever As shown in the drawings, the connecting point 27. between arm 22 and link 23, is below a straight line drawn between pivot 16 and the connecting point 28 at the unction oilink 23 and spring 21.

In this position the tension of spring 21 acts to force spring 18 against pin 19 to open valve 15. If the valve 15 is opened after valve 10 has been opened, then com pressed air will flow from pipe 11 thru pipe ll to pipe 29 to sylphon G to expand it and thereby move ratchet wheel 1 as previously described.

On the shaft 2 a contact maker or wiper 30 adapted to sweep over contact points 81, to each one of which are connected the wires 82 extending to other points in the exchange. Another wire 33 extends from the wiper 30 to a magnet 34. and thence to battery X. and ground at 35. It will be obvious that as the wiper 30 is advanced step by step over the contacts 31, the battery X and magnet 34 will be connected in succession to the wires 32. If one of these wires has on it a ground connection, as indicated by dotted lines for the first wire 32. then a circuit will be completed thru the magnet 3 and that magnet will become energized. But if there is no ground connection on a wire 32 at the time the wiper 30 reaches it, then no circuitwill be completed thru magnet 33%.

The armature 36 of the magnet 341- has a notch 37 adjacent to the lever 4t and so arranged that if the magnet 3 1 is energized at the time the lever at is advanced by the sylphon, then the notch 37 will engage the lever 41 and hold it from falling back when air is exhausted from sylphon 6. This mechanism forms a lock for interrupting the automatic advance of the wiper.

The present apparatus is for use in finding an idle trunk connection between different parts of an automatic telephone exchange. The different trunks are represented by the diiierent wires A trunk is idle when there is a ground connection on the corresponding wire 32, and is busy when the wire has no such ground connection. The present problem is simply that of find ing which one of several wires has on it a ground connection at the time the apparatus operates, and the apparatus is useful tor that purpose independent of the conditions the ground connections are made unmade.

The apparatus is set into operation by connecting wires 8 and 9 to each other to complete a circuit thru magnet 7. This attracts arma-ture 13 to open valve 10 and permit compressed air to flow to valve 15. In normal position, valve 15 is open, and consequently the opening of valve 10 admits air to the sylphon 6 which expands to move lever 4 and advance wheel 1. In this movement of lever 4, the arm 26 strikes the arm 24 and moves the lever pivoted at 16 to its alternative position in contact with the stop 38. In this position the spring 18 leaves pin 19 and valve 15 closes under pressureof the air in pipe 14. Thus cutting oil the air supply to sylphon 6 permits it to contract and move lever 4 back to normal position. In this movement the arm 25 strikes the arm 24 with the result that the spring 18 again opens valve 15 and the sylphon again advances the ratchet wheel. In this advance the valve 15 is again closed and the operations are repeated. In brief, the apparatus is a form of interrupter which automatically advances the wiper step by step over the contact points 31 whenever a circuit is completed thru the magnet 7. It may be understood that the speed of operation of the sylphon 6 can be regulated in any well known manner, for instance, by a regulating device such as illustrated in connection with the sylphon 40; When the wiper comes to a contact point having a ground connection, a circuit is completed thru the magnet 34 and the notch 37 is thrown under the end of the lever 4 and prevents that lever from falling back when the valve 15 closes as described. Under these conditions the apparatus is brought to rest in a position which corresponds to that of a non-busy trunk.

Pipe 14 has a branch 39 which extends to a sylphon 40, and from this sylphon there is a connection 41 which serves to hold the holding pawl 42 away from ratchet wheel 1 when the parts are in normal position.

'lVhen air flows thru pipe 14 by reason of and the opening of valve 10, it also flows to sylphon 40 which expands and permits hold-' 34 and the battery X are contact openings 43 and 44. iVhen the parts are in normal position, a collar 45 on the sylphon 40 engages spring 44 to hold it from spring 43, but as soon as air is admitted to sylphon 40 these springs close.

iWhen the wiper 30 comes to rest on a terminal 51 of an idle trunk, the parts stand in that position until the circuit is broken thru the magnet 7. When this occurs air is cut off from pipe 14 and the sylphon 40 returns to normal position under the action of a retracting spring 46. This breaks the connection between springs 48 and 44, and consequently the circuit for magnet 34. The armature 36 then falls back and releases the lever 4which also falls back to normal. As the return of the sylphon 40 releases the holding pawl 42, the ratchet wheel 1 is free to return to normal position in the ordinary manner.

lVhat we claim is:

1. The combination terminals, and a wiper arranged to be moved so as to engage said terminals in succession, of a pneumatic motor and an air valve arranged to control each other to operate the motor to advance the wiper step by step, a magnet arranged to have its circuit closed by the wiper when coming upon the terminal of an idle trunk, and means actuated by said magnet for a resting the advance of the wiper.

2. The combination with a series of trunk terminals, a wiper, and a ratchet and pawl mechanism, pneumatic devices arranged to automatically actuate said mechanism to move the wiper to successive engagement with different terminals, and stopping means controlled thru the terminal of an idle trunk for arresting the mechanism when the wiper reaches such terminal.

The combination with a series of'trunk terminals, a wiper. and a plurality of pneumatically operated devices for automatically advancing the wiper to successive engagement with diiterent terminals, of a locking device arranged to stop the operation of the pneumatic devices, and means for controlling said locking device thru the terminal of an idle trunk.

with a series of trunk 4. In a trunk selecting switch of an automatic telephone exchange, a movable element, a pneumatically operated interrupter for moving said element, and a' locking device, for arresting the oper'ations'ot the interrupter to stop the element.

5. The combination with a series of trunk terminals, a wiper, a plurality of A pneumatically opera-ted devices for automatically advancing the wiper step by step to suecessive engagement with differentterminals, of a locking device arranged to stop the operation of the pneumatic device, and means for controlling said locking device through the terminal of an idle trunk.

6. In a trunk selecting switch, of an automatic telephone exchange, a movable element, a pneumatically operated interrupter for moving said element step by step, and a locking device for arresting the operations of the interrupter to stop the element.

T. An interrupter consisting of a movable element, a motor for cont-rolling said element, a device for controlling the operation of said motor, and atogglearrangement for operating said device, said element having reciprocating movements arranged to operate said toggle arrangement at the extreme limits of its reciprocating movements to operate said device.

8. A pneumatic interrupter consisting of a movable element, a pneumatic motor for controlling said element, an air valve for cont-rolling the operation of said motor, a toggle arrangement for operating said valve, said element, having reciprocating movements and arranged to operate said toggle arrangement at the extreme limits of its reciprocating movements to operate said valve.

9. An interrupter consisting of a movable element, a motor for operating said element, a source of energy for operating said motor, a normally open device for controlling the operation of said'motor, a toggle arrangement for controlling the operation of said device, means for admitting said source to said motor to cause the operation thereof, the operation of said motor causing said element to move to its Working position, said element in moving to its working position causing the operation of said toggle arrangement, said toggle arrangement closing said normally open device to cut ofi said source of energy from said motor, and means for returning said element to normal position after said source of energy is cut off from said motor to operate said toggle arrangement a second time to return said device to its normal position.

10, An interrupter consisting of a movable element, said element having normal and advanced positions, a motor for operating said element, a toggle arrangement for controlling the operation of said motor, means for operating said motor to move said element to its advanced position, said toggle arrangement remaining in normal position until said element has reached its advanced position, said element upon reaching its advanced position causing the operation of said toggle arrangement to its alternate position, means for returning said element to normal position, and said toggle arrangement remaining in its alternate position until said element reaches its normal position.

11. In a telephone system, trunk terminals, a wiper, a pneumatic motor, and a source of compressed air for operating said motor, means for operating said motor to move said wiper into engagementwith one of said trunk terminals, and means controlled by the operation of said motor for intermittently interrupting said source of air to said motor to cause said wiper to be advanced step by step into successive engagement with said trunk terminals until an idle trunk terminal is found.

12. In a pneumatic switch, a pneumatic motor, and a source oi compressed air for operating said motor, and means controlled by the operation of said motor for intermittently interrupting said source to intermittently operate said motor.

13. An electro-pneumatic interrupter consisting of, two electro-magnets, a normally open air valve, a normally closed air valve, a locking device, and a pneumatic motor, a source of air pressure, means for energizing one of said electro-magnets to operate said normally closed valve to connect said source to said motor to cause the operation thereof, means operated by said motor in its operated position for closing said normally open valve to cut off the source from said motor to cause said motor to return to normal position, said last-mentioned means again operated by said motor returning to normal position to open said normally open valve to again connect said source to said motorto cause the operation thereof, means for operating said second electro-magnet, ands-aid locking device operated by said second electromagnet for locking said motor in operated position.

14. An electro-pneumatic interrupter consisting of two magnets, a normally open air valve, a normally closed air valve, a pneumatic motor, a locking device, a switch wiper and trunk terminals, a source of air pressure, means for operating one of said magnets to operate said normally closed valve to connect said source to said motor to cause the operation thereof, said motor operating said wiper into engagement with one of said trunk terminals, means operated by said motor in its operated position for closing said normally open valve to cut off the source from said motor to cause said motor to return to normal position, said last-mentioned means again operated by said motor returning to normal position to open said normally open valve to again connect said source to said motor to cause the operation of said motor to move said wiper to an ad-. jacent one of said trunk terminals, means for operating said second magnet through the trunk terminal of an idle trunk and said locking device operated by said second magnet for locking said motor in operated position and for locking said wiper in engagement with an idle one of said trunk terminals.

15. An electro-magnetic interrupter consisting of two magnets, a normally open device, a normally closed device, a motor, a locking device, a switch wiper and trunk terminals, a source of power, means for operating one of said magnets to operate said normally closed device to connect said source to said motor to cause the operation thereof, aid motor operating said wiper into engagement with one of said trunk terminals, means operated by said motor in its operated position for operating said normally open device to cut oil. the source from said motor to cause said motor to return to normal position, said last-mentioned means again operated by said motor returning to normal position to operate said normally open device to again connect said source to said motor to cause the operation of said motor to move said wiper to an adjacent one of said trunk terminals, means for operating said second magnet through the trunk terminal of an idletrunk, and said locking device operated by said second magnet for locking said motor in its operated position and for locking said wiper in engagement with an idle one of said trunk terminals.

16. An electro-pneumatie interrupter consisting of two magnets, anormally open air valve, a normally closed air valve, a pneumatic motor, a switch wiper and trunk terminals, a source of air pressure, means for operating one of said magnets to open said normally closed valve to connect said source to said motor to cause the operation thereof, said motor operating said wiper into engagement with one of said trunk terminals, means operated by said motor in its operated position for closing said normally open valve to cut oil the source from said motor to cause said motor to return to normal position, said last-mentioned means again operated by said motor returning to normal position to open said normally open valve to again connect said source to said motor to cause the operation of said motor to move said wiper into engagement with the next adjacent trunk terminal, and means for operating said second magnet through thetrunk terminal of an idle trunk to maintain said Wiper in engagement therewith.

17. In a pneumatic interrupter, a pneumatic motor, means for supplying a steady flow of air to said motor to cause the opera tion thereof, means operated by said motor inits extreme operated position for intercepting said flow of air to cause said motor to return to normal position, said last-meir' tioned means again operated by said motor in its normal position to again connect air to said motor to cause it to move to operated position, a locking device, and means for operating said locking device to lock said motor in operated position. 1

18. In a pneumatic interrupter, a pneumatic motor, a source of air pressure, means for connecting said source to said motor to operate the same, and a normally open air valve operated by the operation of said motor for intermittently interrupting the source to intermittently operate said motor.

FRANK A. LUNDQUIST. JOHN A. KROPP. 

